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The First Earthbag House in Jamaica Nicola Shirley-Phillips

Introduction Building a house in Jamaica is often a daunting task. Most, if not all, households in the higher income groups have moved away from self-building, transferring the construction of their dwellings to professionals and skilled and certified craftsmen. Working-class households, however, have had to get increasingly involved in the construction of their dwellings1. Some have become site inspectors, watching how their hard-earned money is spent and ensuring that they get what they pay for. On occasion, some owners have had to jump in, roll up their sleeves and get physically involved in the construction. This was how I became involved in building the first Earthbag House in Jamaica. The challenge was, "How do I build a strong and durable building, with limited funds, that would withstand the now almost yearly hurricanes and the potential earthquakes, using natural materials which would have a low impact on the environment and that could be completed in a limited amount of time?" Initially, this was an almost impossible question to answer. I did not have any building construction, engineering or architecture background. This paper traces my journey from impossible to actual. Conducting the research I persisted in posing the question to my friends and associates until, finally, a young man suggested, 'Just use one of the natural building methods. You could probably use the Earthbag building method in Jamaica'. What was the Earthbag method? Trying to find the answer led me to the Internet and a world of possibilities. I remembered as a child playing in dirt and making mud houses and sand castles and realized that those games were finally going to pay off. The solution to my housing dilemma was under my feet - dirt, earth, marl, sand, clay.

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Virtually all units in informal settlements are self-built.

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I discovered that about half the world's population, approximately 3 billion people on 6 continents - Antarctica was excluded - live or work in buildings constructed with earth. (Minke, 2006) Earth construction techniques have been known for over 9,000 years. Mud brick (adobe) houses, dat- Photo 1: Great/Grand Mosque in Bamako, Mali ing from 8,000 to 6,000 B.C., have been discovered in Russian Turkestan. Rammed earth foundations, dating from around 5,000 BC, have been observed in religious buildings. The largest earthen building in the world is the Great Mosque of Djenne, Mali built in 1907. It is one of the most famous landmarks in Africa. Much of the Great Wall of China, particularly the earliest stretches, were constructed with rammed earth, a precursor to earthbags. The Ait Benhaddou, a city in Morocco, was constructed of earth. I learned about the Native American adobe builders of the Southwest and their Pueblo-style earthen buildings. I came across the picturesque earthen cottages in Devon, England. These whitewashed cottages with thatched roofs using the cod style of earthen building and dating back to the 1500's are the quintessential English Country cottage. I also found that our forefathers here in Jamaica constructed buildings with wattle and daub, another earth building method. A number of these houses are still standing and habitable today. The style of earthen building that intrigued me was the Earthbag method, or Super Adobe as it is called by its originator Professor Nadiar Khalili from the California Institute of Earth Art and Architecture. Professor Khalili is an architect/author and was commissioned by

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NASA to create a possible building solution for building off-planet. Professor Khalili's recommendation was to use compressed, stabilized earth and put this mixture in bags to be used as building blocks. With this method, the space shuttles would only need to carry lightweight bags, shovels and barbed wire. Unfortunately, it has been argued that the payload of dirt could still pose unsurmountable weight problems. Khalili realized that this inexpensive system could be used, too, here on earth in remote locations and in disaster-prone areas. He proposed that, during times of natural disasters, aid organizations could air-drop bags and shovels in affected Fig. 1: Location of St. John's Town locations and people could quickly build temporary, simple, sturdy structures to replace damaged or destroyed homes. But Earthbag construction was not only for housing under unusual conditions. It was perfectly suitable for 'ordinary', permanent housing. All the material for an Earthbag unit - bags (polypropylene, burlap or rice bags), barbed wire and chicken wire - were available in Jamaica and relatively inexpensive. The bulkiest ingredient was soil and marl and I had plenty since I had to excavate the site before I started to build. I would use this material to fill the bags and construct my house. The site, located on privately-owned land in John's Town, St Thomas, was on a limestone hill-side and had to be levelled. I visited Professor Khalili's website and studied everything I could about the construction process. I researched other Earthbag builders and looked at photos of completed projects. I thought about taking a workshop at the California Institute of Earth Art and Architecture but could not overcome the constraints of lack of time and funds. So I bought one of Khalili's instructional videos.

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The video showed me how to construct an Earthbag domed structure. As an aside, I learnt that few structures in nature are square: domes and curves occur much more frequently in the environment. And domes are the best building form for areas prone to high winds and storms. However, although I liked the dome structure, I was not sure if it was not too 'adventurous' for Jamaica's culture. Despite all that research, actually constructing a dome was going to be a stiff test as my first attempt at building a structure from the ground up. I also had to take into account the construction workers who were available in the community, their skill level and their (lack of) familiarity with the Earthbag technique. However, if the method succeeded and was low cost and required limited skills, it could help solve the formidable housing problem of Jamaica's working class. I decided to throw caution to the wind and attempt the first Earthbag sample unit in Jamaica. Getting started My brother played a vital role in the design and in the building process. He was completing a Masters degree in Design and needed a thesis project to graduate. We decided to collaborate and use this building for his thesis. We knew that Jamaicans are 'show me' people: if we could build one and people could see and touch the product - in short, if they could deduce the merits of its construction for themselves - we would open up a window for the method. Then there was the matter of building approval, which was the responsibility of the St Thomas Parish Council. Official approval was important since it is a pre-requisite for insurance and for securing loans from formal sector lending agencies such as the NHT. We decided to come clean with the Parish Council's building inspector. We showed him the video and explained it was going to be a thesis project and a sample building. We also explained that this project would be on our privately owned land. The inspector did not give us official permission but thought the idea revolutionary. So we decided

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to follow our Grandmother's advice: 'Sometimes, child, it is better to ask for forgiveness than permission'. Another hurdle was in convincing the masons and other workmen that this was a sound building method. The head mason was HEART-trained and had been building traditional block and steel houses for all of his construction career. When I first brought the Earthbag idea to him he looked at me as if I was crazy. I then showed him sample buildings on the Internet after which he conceded, 'Ok, you are not so crazy'. However, he was unsure if it would work in Jamaica. After I got the video, I gave it to him. He must have watched the video 20 times before he was persuaded to give it a try. We also let the other construction workers watch the video to help them understand what we planned to do. For their part, our neighbours were laughing at this 'bag house' idea and they, too, initially thought I was crazy. Building the unit We decided to use polypropylene bags. They were filled with a mixture of marl and/or soil, which we had excavated from the building site. Immediately prior to laying, this material was mixed with cement and slightly moistened. We had read that the amount of water should make the mixture just damp enough to form into ball when compressed in your hands. This advantage of the method made it great for places that have limited water or access to water. We used 55cm bags (55cm x 90cm) for the walls because this was what was available at the time so the walls are thick. From what I found out in my research,30. 5cm to 61cm bags can be used. It all depends on what is being constructed. Many persons seem to prefer 43cm to 45cm bags. The Earthbag building process is simple and follows many of the building `laws' of block and steel construction. This is what we had seen on the Professor Khalili's video Eco-Dome:Building a Small House. In block and steel construction, the foundation is dug 46cm to 61cm.

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However, in an Earthbag building it is necessary to dig only 15cm to 20cm on the depth of solid earth . It is important to place stabilized earth (earth mixed with cement and water) in the first few layers of bags to ensure a solid base as Photo 2: Earthbag unit under construction in Haiti Note the staggered pattern in laying the bags well as to protect against moisture wicking (water being absorbed from the surface area and surrounding top soil). One bag was filled to within 10 to 12mm from the top, its ends folded or pinned with a nail and then it was laid in a bag stand. The next bag was filled and closed and abutted the previous bag as is done with traditional block and steel construction. Once a row was laid, the bags were tamped to compress the filling material. The bags are laid in a similar fashion to traditional blocks, with two strands of 4-point barbed wire laid on top of each layer. The barbed wire holds the filled bags in place until they harden and set. In the case of windows and doors, a frame is placed in the opening and the bags laid around them. Where there is a header or lintel for a door or window,

Photo 3: Image showing the width of the wall an attraction for some, a problem for others

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steel is hammered into the bags for extra strength and to span the opening. The bags are laid up to the level of the ceiling and a concrete bond beam is poured and roof is attached. Any type of roof can be used on an earthbag foundation. We had abandoned the idea of a dome and installed a concrete slab roof because we wanted a `green roof' above the building and one which could be used as a water catchment. Most importantly, St. Thomas gets every landfall of storms and hurricanes: any other type of roof would be much riskier. The construction was simple but not without some moments of anxiety. It was straightforward to fill the bags and friends and family assisted us in filling all 3,500. The anxiety came when we had to lay the bags and figure out if we were doing it correctly. I give full credit to the construction crew because, as soon as the bags started to come out of the ground and the crew saw the walls start to take shape, they took over the process. They made suggestions for improvement, formulated some `inventions' and modifications to the method and really fell in love with the process. All of them decided that they were going to build their new houses or make additions to existing ones using this method because of the ease and cost of construction. Eventually, the construction crew began to give tours of the worksite and I knew they were not laughing at me and my crazy idea anymore. The major highlight for the crew was when the house was seen on the popular Television Program Hill & Gully Ride. The house took longer than we had imagined due to a lack of funding but we estimated it would have taken three months if the project were fully funded. The structure was 9.1m x 8.8m or about 80.8sqm. It was a one-bedroom, one-bathroom (large), kitchen with dining and a large living room. Among its interesting features are that it was built in the Southwest America Adobe style; all the walls and corners were rounded and the house has a `natural' feel to it. The beams are of coconut wood, for its decorative effect, and were cut from dying coconut trees on the property. A number of solar light tubes in the ceiling let in sun and moonlight. This has reduced the need for electric lights.

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The floor is a simple, poured concrete floor with red ochre mixed in. The rendering for the wall contains green, orange and blue pigments. I wanted to do this to reduce the cost of painting each year. The thick walls created a thermal mass causing the house to be cool in the heat of the day. One unexpected feature was that the house has a `good feeling' to it, it is comfortable. As a visitor noted,`It feels as if you are in the womb'. And yet, the house has all the modern conveniences sinks and toilet with all the traditional fixtures. The only thing that was not yet completed at the time of writing was installation of electrical outlets and lighting fixtures. The cost of the house, material and labour, was J$1.35 million. Lessons Learned After the completion of the Earthbag we had a number of visitors. One of them, a permaculture expert and natural builder teacher from Earthaven Ecovillage in North Carolina, did some analysis of the method of construction we had devised on the run. According to him, we did not need to use cement in all the bags. [This is what we had seen on the video but I had noticed that white marl had a tremendous adhesive ability Photo 4: Section of wall showing exposed and compressed well in the chicken wire used as base for rendering or bags.] The expert explained plastering. Observe, too, the pipes laid in that, because of this ability, the walls. using compressed marl was like using a cement. We could have filled some bags with marl alone. In addition,

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the fact that we used chicken wire and rendered the walls with cement had made the structure super strong and durable. All this after we had engaged in fundraising efforts and had spent a substantial fraction of scarce funds buying cement to fill all the bags! Another visitor and Earthbag expert, Stephen Kemble, confirmed this after he had done a soil test on the marl. Stephen also mentioned that we did not have to lift, and should not have physically lifted, a single filled bag. The bags could be filled in place using bags stands. Of course, we had filled 3500 bags and then moved them into place. He informed me of other cost savings methods and processes which could have reduced the cost from $1.3 million to about a half of that. Stephen recommended we purchase a manual on Earthbag construction, Earthbag Building:The Tools,Tricks and Techniques, written by Khaki Hunter and Donald Kiffmeyer. Other persons have visited to look at the Earthbag House and it has had a great impact on each of them, as well as on the community of Johns Town. For over 20 years, the community had been struggling unsuccessfully to secure enough funds to build a community centre, until the Earthbag technology was introduced. Recently, the Member of Parliament offered Ja$2,000,000 to the Johns Town Community Development Committee. This sum, together with community labour, will be sufficient to complete the project. The greatest response has been from women coming to view the house because

Photo 5: Almost completed earthbag house. Quite 'normal-looking' from outside.

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they are often the segment of the population suffering most from the lack of proper housing for themselves and their children. We have had several enquiries and requests from schools seeking inexpensive solutions for classroom additions. A number of private developers have stopped by and one in particular is planning on building 200 units in St. Catherine using this technology. Experience is always the best teacher. I learned a lot during the building of the Earthbag house and am even more convinced that this building system is appropriate for Jamaica. We have an abundance of marl, the best building material for this system. The cost of constructing an earthbag house is considerably lower than a traditional block and steel building of the same size. The ability of all age-groups to participate in the construction process and the ease of learning the method are positive factors. Importantly, earthbag construction can have a low impact on the environment. It uses less cement and less steel and, often, the material that is excavated from the site can be used to fill the bags. Earthbag houses have a good earthquake rating. A building consultant, assessing the unit on behalf of one the island's largest insurance companies, noted that the structure could be favourably considered for insurance. My earthbag house has withstood two hurricanes and a number of tropical storms. This house will be here long after I am gone and I will have something to pass down to my children and grand-children. Dirt and earth are part of the foundation elements of the planet and play a vital role in our survival. It seems right that we should use them to satisfy our need for shelter. So I guess I really haven't stopped playing in dirt.

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References

Hunter, Khaki and Doni Kiffmeyer, Earthbag Building:The Tools, Tricks and Techniques, New Society Publishers, BC, Canada (2004). Minke, Gernot, Building With Earth: Design and Technology of a Sustainable Architecture. Birkhauser Pub Ltd. Basel, Switzerland (2006). Photos Photo 1 - 8 2007 University of Oregon: International Affairs. Study Abroad Programs. http://studyabroad.uoregon.edu/africa/mali/sit bamako1.html 14 May 2009 Photo 2 - The Sun House:Sharing information and promoting Earthbag building . www.earthbagbuilding.com/projects/haiti.htm 7 May 2009 Photos 3 - 4 and 6 - 8 Maurice Anderson Photo 5 - Nicole Shirley-Phillips

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APPENDIX A:The components

The Fill A soil ratio of approximately 30 percent clay to 70 percent sand is ideal. More clay does not make for a stronger building material. When wet, clay is both sticky and slippery and, when dry, can be mistaken for fractured rock. Sands and gravel, on the other hand, remain stable when wet and dry. This is why it is important to have a low ratio of clay in the soil that will be used. The sand:clay ratio determines how much cement will be needed to stabilize the earth. There are some exceptions to this rule. Marl, which is found over much of Jamaica, has a very low clay content and pure white marl has been found to be the best material for the type of earthbag construction discussed in the paper, mainly because of its compressibility. Using white marl will substantially reduce the amount of cement needed to stabilize the earth thus reducing the cost of building materials. The basic idea around earthen construction is that the soil must be able to be compressed in the bags leaving no space or air pockets and creating a dense, solid form. The Bags The bags which are commonly used in Earthbag construction are the feed or grain bags that are in common use. Often these bags are made of polypropylene. These bags come in various sizes from 30cm to 61cm in width. Other bags such as burlap are well-suited for this use as well. These bags can be purchased from a manufacturer or collected from persons who acquired them and need to dispose of them. The bag size is selected to fit the particular project. The 30cm bags are well-suited for constructing retaining walls and are often used in dome construction. We used 53cm bags because that was what was available but 40 and 46cm 8 inch bags work well for walls and save on fill. Recently, some manufacturers have been putting a non-skid coat onto polypropylene bags. This reduces the breathability of the fabric, keeping the earth from being able to dry out and cure effectively. You must inquire, prior to purchasing, that the bags are not treated. Also, polypropylene bags are designed to break down once exposed to sunlight. It is important that the bags are stored out of direct sunlight and that you plan your building project to avoid leaving unrendered walls exposed to UV for months at a time. Once a wall is constructed, the walls should be rendered or plastered. Polypropylene bags will not break down once the wall is covered and will not give off gas as other polyethylene bags.

The First Earthbag House in Jamaica Burlap bags are an excellent product for this type of construction. They bags will hold up to the sun in desert climates for years once kept up off the ground and as long as their seams have been sewn with UV resistant thread. The polypropylene and burlap bags both come in tubes from manufacturers. Tubes are often more cost effective and inexpensive. Tubes also allow you to do longer runs of walls or create curves and are very flexible. Barbed Wire Two strands of 4-point barbed wire are placed along every row of bags and acts as a Velcro mortar. This cinches the bags together and provides tensile strength that inhibits the walls from being pulled apart. Tensile strength is something that most earthen architecture lacks. The barbed wire, aided by the tensile quality from the woven polypropylene bags, provides a ratio of tensile strength unique to Earthbag construction. This allows for the construction of corbelled domed roofs as the 4point barbed wire gives a sure grip that enables the bags or tubes to be stepped in every row until gradually the circle is enclosed. Chicken Wire Chicken wire is attached to the earthbag walls by the use of tie wires (binding wire). The chicken wire is a medium which allows cement stucco (rendering) to adhere. Chicken wire is not always used on Earthbag walls if other plasters are used to cover the bags. However, in the Caribbean, with our extreme weather conditions, it is recommended that a cement stucco is used as wall cover and chicken wire is an inexpensive medium to hold that stucco to the bags. APPENDIX B: Advantages of building with Earthbags Strength. An Earthbag wall is extremely strong, owing to its thickness and weight, thus it is unaffected by high winds or other destructive forces. Versatility. The Earthbag system can use a variety of fill materials, often obtained from the site itself. The bags themselves can be made from either synthetic or natural material depending on the application. The fill can be stabilised with cement or lime for the construction of foundations. Posts, Beams and Lintels. Posts and beams can be built into the wall structure with ease, allowing for multi-level construction. Window lintels are easily incorporated into the wall. Adaptable. It is easy to alter the position of wall openings during construction, or even to dismantle an incorrectly placed wall and rebuild it with the very same materials. Services. Plumbing, electrical and other services are very easy to incorporate into the Earthbag wall as it is built, which can significantly reduce plumbing and electrical contractor input and hence cost.

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Plaster. The plaster can either be cement or clay and lime based, depending on application. The plaster will cure slowly when applied over a dampened Earthbag, rather than drying rapidly on a block or brick. Plaster strength is therefore enhanced. Security. There are no piles of bricks on site that may be subject to theft, just the bags which are easily secured and a pile of earth which has no value. Remote locations. As only the bags need to be transported to the site, provided suitable earth is found on site, it allows for easier construction in remote locations. A small car or van would be sufficient. When this is not the case, earth/marl has to be transported to the site. Water. As water is often in short supply, the advantage of the Earthbag system that uses minimal water in construction is great. Water is then only required for plastering. Site Clearing. There is minimal waste material generated using the Earthbag system, and expensive site clearing bills are thus avoided. Economic considerations The Earthbag system is a very cost effective method of construction. Skill requirement. The level of skill required is low as the method, once demonstrated, is very simple. Plastering is the only skill that may be required if a superior level of finish is desired. Labour requirement. Labour intensive,a plus in a labour surplus situation. Speed of Construction. Rapid, as there is no skilled bricklaying to be done and the method is easily learned. Market Value. `Green' buildings are rapidly commanding premium prices in international property markets and so the retail value can be expected to increase faster than the average. Aesthetics Timeless. A house built with earth, especially using natural plasters and other natural materials, is a structure of beauty. The comfortable microclimate, colour, texture and feeling of permanence imparted is unmatched, as can be experienced in many of our historic monuments. User Friendly Construction Method Easy to learn. Earthbag building is easy to learn, and can therefore be mastered by unskilled people in a very short time, with minimal supervision. It can be an ideal community-based building system.

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Thermal, acoustic and climate control qualities Thermal Efficiency is excellent. Houses are cool in summer and warm in winter. The insulative value of an Earthbag-sand wall is approximately 9 times that of a concrete block wall. You would need to build a block wall 1. 8m thick to achieve the same insulation value. Soundproof. The Earthbag wall is a superb insulator of sound, and the interior will be quiet and peaceful. When used as an interior wall, Earthbag construction will allow for privacy between rooms. Fire Resistance. Excellent. Bullet-proof. Unfortunately, a desirable advantage these days.

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